Casio HK1223 - Manual (Page 95)

Setup Configuration Utility (SCU) 5-5
Internal Numlock
Sets if you can enter a number when Num Lock is turned off. When this
item is enabled, you can press and hold Fn , and then press a letter key to
enter a number even if Num Lock is turned off. When this item is disabled,
you cannot enter a number with the above method. A check mark ( )
indicates enabled while underline (_) indicates disabled. Default setting is
enabled.
USB Emulation
Enables or disables the system’s support for the USB port in DOS mode.
A check mark ( ) indicates enabled while underline (_) indicates
disabled. Default setting is enabled.